D1
Department of Nuclear Engineering and Management, School of Engineering, the University of Tokyo
Current Research Theme
First-principles calculations of electron dynamics in amorphous solids under ultrashort laser pulses
Education
04/2025 – present Doctor’s course, Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo
04/2023 – 03/2025 Master’s course, Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo
04/2021 – 03/2023 Department of Systems Innovation, Faculty of Engineering, The University of Tokyo
04/2019 – 03/2021 Natural Sciences I, College of Arts and Sciences, The University of Tokyo
Journals
Tomohito Otobe, Eiyu Gushiken, Influence of point defects on laser-induced excitation in silicon, Phys. Rev. Applied 22, 064096 1-9 (Dec. 30, 2024) (DOI: 10.1103/PhysRevApplied.22.064096)
Academic Conferences
<2025>
Eiyu Gushiken, Tomohito Otobe, Hiroki Katow, Arqum Hashmi, Mizuki Tani, Shunsuke Yamada, and Kenichi L. Ishikawa, “First-principles calculations of high-harmonic generation in amorphous Si and SiO”, 10th International Conference on Attosecond Science and Technology, The Science Village Hall, Lund, Sweden, 07/2025 (Poster)
Eiyu Gushiken, Tomohito Otobe, Hiroki Katow, Arqum Hashmi, Mizuki Tani, Shunsuke Yamada, and Kenichi L. Ishikawa, “First-principles calculations of excitation dynamics in amorphous Si and SiO driven by intense laser pulses”, The 9th International Congress on Laser Advanced Materials Processing, Sinfonia Technology Hibiki Hall Ise, Mie, Japan, 06/2025 (Oral)
Eiyu Gushiken, Tomohito Otobe, Hiroki Katow, Arqum Hashmi, Mizuki Tani, Shunsuke Yamada, and Kenichi L. Ishikawa, ”Wavelength dependence of energy transfer from femtosecond laser double pulse to silicon”, The 6th UT2-MAC Student Workshop, Hongo Campus, The University of Tokyo, Tokyo, Japan, 06/2025 (Oral)
Eiyu Gushiken, Tomohito Otobe, Hiroki Katow, Arqum Hashmi, Mizuki Tani, Shunsuke Yamada, and Kenichi L. Ishikawa “First-principles calculations of energy transfer from femtosecond laser pulse to amorphous silicon monoxide”, The 72th JSAP Spring Meeting 2025, Noda Campus, Tokyo University of Science, Chiba, Japan, 03/2025 (Oral)
<2024>
Eiyu Gushiken, Tomohito Otobe, Mizuki Tani, Shunsuke Yamada, Hiroki Katow, and Kenichi L. Ishikawa, “First-principles calculations of excitation processes in amorphous silicon by femtosecond laser pulses”, International School and Symposium on Nanodevices and quanTum Technologies, NTT Atsugi R&D Center, Kanagawa, Japan, 12/2024 (Poster)
Eiyu Gushiken, Tomohito Otobe, Mizuki Tani, Shunsuke Yamada, Hiroki Katow, and Kenichi L. Ishikawa, “Ab-initio calculations of energy transfer from femtosecond laser pulse to amorphous silicon”, Quantum Beam Application for Sciences and Industries 2024, SANKEN, Osaka University, Osaka, Japan, 11/2024 (Poster)
Eiyu Gushiken, Tomohito Otobe, Mizuki Tani, Shunsuke Yamada, and Kenichi L. Ishikawa “First-principles calculations of energy transfer from femtosecond laser pulse to amorphous silicon”, The 85th JSAP Autumn Meeting 2024, TOKI MESSE, Niigata, Japan, 09/2024 (Oral)
Eiyu Gushiken, Mizuki Tani, Hiroki Katow, and Kenichi L. Ishikawa, “Electron Energy Absorption in Silicon by Femtosecond Laser Double Pulses of Different Wavelength Combination”, The 5th UT2-MAC Student Workshop, McMaster University, Ontario, Canada, 05/2024 (Oral)
<2023>
Eiyu Gushiken, Mizuki Tani, and Kenichi L. Ishikawa, “Electron excitation dynamics in silicon irradiated by femtosecond double pulses of different wavelength combination”, XXXIII International Conference on Photonic, Electronic and Atomic Collision, Shaw Centre, Ottawa, Canada, 07/2023 (Poster)
Eiyu Gushiken, Mizuki Tani, and Kenichi L. Ishikawa, “Wavelength Dependence of Energy Transfer from Femtosecond Laser Double Pulse to Silicon”, CREO®︎/Europe 2023, International Congress Center Messe München, Munich, Germany, 06/2023 (Poster)
Eiyu Gushiken, Mizuki Tani, and Kenichi L. Ishikawa, “Enhanced energy absorption in silicon by femtosecond laser double pulses with different wavelengths”, The 24th International Symposium on Laser Microfabrication, Hirosaki Bunka Center, Aomori, Japan, 06/2023/ (Oral)
Eiyu Gushiken, Mizuki Tani, and Kenichi L. Ishikawa, “Wavelength dependence of energy transfer from femtosecond laser double pulse to silicon”, The 4th UT2-MAC Student Workshop, Komaba Campus, The University of Tokyo, Tokyo, Japan, 05/2023 (Oral)
Eiyu Gushiken, Mizuki Tani, Hiroki Katow, Kenichi L. Ishikawa “Wavelength dependence of energy transfer from femtosecond laser double pulse to silicon”, The 70th JSAP Spring Meeting 2023, Yotsuya Campus, Sophia University, Tokyo, Japan, 03/2023 (Oral)
Thesis
Master’s theses “First-principles calculations of energy transfer from femtosecond laser pulses to single-crystal silicon and amorphous materials” (Supervisor: Prof. Dr. Kenichi L. Ishikawa)
Graduation thesis (Bachelor) “Wavelength dependence of energy transfer from femtosecond laser double pulse to silicon” (Supervisor: Prof. Dr. Kenichi L. Ishikawa)
Awards
- FY2024 Dean’s Award, ”First-principles calculations of energy transfer from femtosecond laser pulses to single-crystal silicon and amorphous materials”, School of Engineering, The University of Tokyo, 03/2025
- Student Poster Award Grand Prize “Ab-initio calculations of energy transfer from femtosecond laser pulse to amorphous silicon” (Q-BASIS 2024)
Message
Light is such a familiar presence to humans that many of us don’t consciously think about it in our daily lives. However, upon reflection, we can realize that it is an incredibly mysterious concept. Our lab is conducting cutting-edge theoretical research on quantum technologies such as lasers and quantum computers. In particular, I’m interested in how strong lasers and matter interact on the time scale of femtoseconds and attoseconds (0.000000000000000001 seconds). There are countless stories in your life although it is just a fleeting moment in the universe. Even if it is a fleeting moment for us, there would be compelling stories between light and matter.
